import os
from pathlib import Path

class Log:
    def __init__(self, path):
        self.path = path
        header = ["epoch","avg_txt","avg_enc","avg_dec","txt_loss","masking_loss","prediction_loss"]

        if Path(path).is_file():
            return
        
        with open(self.path, "w", encoding="utf-8", newline="") as f:
            f.write(",".join(header) + "\n")

    def write(self, loss: list[float]):
        line = ",".join(str(float(x)) for x in loss) + "\n"
        with open(self.path, "a", encoding="utf-8", newline="") as f:
            f.write(line)
            f.flush()
            os.fsync(f.fileno())  # extra durability per write # suggested against sudden crashes since it will be done